WASHINGTON (Reuters) - The U.S. House of Representatives on Thursday defeated a sugar amendment to the sweeping farm bill, bolstering the likelihood the House could approve it this week if a Republican standoff over immigration is resolved.

The amendment to the $867 billion bill to limit price supports for domestic sugar production offered by Republican Representative Virginia Foxx was defeated in a 278-to-137 vote.

House Agriculture Committee Chairman Mike Conaway and Representative Collin Peterson, the top Democrat on the panel, both opposed the measure.

The farm bill sugar program is a controversial and complex system of guaranteed prices and import quotas that keep U.S. sugar well above global prices. In recent years, lawmakers have overhauled farm programs for cotton, corn and other commodities by curbing key price subsidies, but not sugar.

The sugar amendment’s failure should ease passage of the overall farm bill in the House, where Democrats oppose it for changes it would make to nutrition assistance programs. The Senate is writing its own version of the legislation.

Conservative lawmakers told Republican leaders earlier Thursday the farm bill vote scheduled for Friday should not be held, however, until they are given a chance to consider a bill that would clamp down on immigration.

“We don’t think there should be a farm bill vote until we deal with immigration,” Representative Jim Jordan, a member of the conservative House Freedom Caucus, told Reuters, adding they had relayed the message to leadership.

The Freedom Caucus has about 30 members in the 435-seat House and they have been pushing for consideration of a conservative immigration bill. The group is using the farm bill as leverage for an immigration debate on the House floor in hopes of firming up support from their core voters in the run-up to the Nov. 6 congressional elections.

Asked by reporters why the Freedom Caucus was linking the farm and immigration initiatives, the group’s head, Representative Mark Meadows, said: “This (farm bill) is literally the last must-pass piece of legislation that we have between now and the spending bill that will come up in October.”

Freedom Caucus members have been pushing a bill that would reduce legal and illegal immigration to the United States while giving temporary protections to young immigrants known as “Dreamers,” who were brought to the United States illegally when they were children.